(1) Field of the Invention
The present invention relates to a method of forming a bead on an edge of a plate member, and more particularly to a method of forming a bead on an edge of a structural sheet member such as an automobile body panel or the like. The invention also relates to an apparatus for use in forming a bead on an edge of a plate or sheet member.
(2) Prior Art
It is known to finish an edge portion of a steel plate or sheet, such as an automobile body panel or the like, through hemming or curling the edge portion. Recently, stricter requirements have been imposed in West Germany upon automobile body panel edge forming. For example, the rear edge of a hood or fender panel must be hemmed at a radius of curvature of 2.5 mm R or more, as measured at the outer surface of the panel. With the prior curling process, it has been difficult to continuously carry out curling, with a constant quality of an edge having three dimensions, such as the rear edge of a hood or fender.